1. Field of the Invention
This invention relates in general to rail hopper cars and, more specifically, to longitudinal hood collars.
2. Summary of the Prior Art
Hopper rail cars have long been used to transport particulate material, such as coal, gravel, grain, pressed stone, and the like. In recent years, hopper cars have been made of aluminum and use a steel center sill as a major structural element. The center sill extends from end to end and primarily transmits draft and buff loads through the car. In such hopper cars, it is common to protect the steel center sill from corrosion from the particulate material by using a longitudinal hood made of aluminum. The longitudinal hood intersects the lower portion of the hopper floor sheets at chute locations and the sloped hopper end walls. As a result, a connection is required between the longitudinal hood protecting the center sill and the hopper floor sheets and end walls to insure that lading does not pass between the hood and the floor sheet and come in contact with the steel center sill.
A sealed connection between the hood and floor sheets have in the past been provided by metal-formed or cast collars. Such metal collars are typically rigidly affixed to both the hood and the floor sheets and much of the applied loads due to draft and buff loads are transmitted through the hood member from the center sill to the floor sheet. As a result, high stress points are created in the hood collar from the draft and buff loads which in effect are pulling the longitudinal hood away from the floor sheet. Because of these stress points in prior designs of collars, the connection is subject to cracking and failure of the mechanical fastener. An example of a known aluminum hood collar is disclosed in U.S. Pat. No. 4,884,511 to Hallam et al.
Metallic collars, being rigid in structure, also do not readily conform to varying cross sections of the hood which can cause gaps between the hood and hopper chutes to reduce the effectiveness of the seal. Moreover, the rigidity of known collars do not provide flexibly to conform to variations in cross sections of particular longitudinal hoods. Accordingly, improvements are needed in the design and construction of hood collars for use in railway hopper cars.